code: def test_serializer():
      s = RecordSerializer()
      array_data = [[1.0, 2.0, 3.0], [10.0, 20.0, 30.0]]
      buf = s.serialize(np.array(array_data))
      for record_data, expected in zip(read_recordio(buf), array_data):
          record = Record()
          record.ParseFromString(record_data)
          assert (
              record.features["values"].float64_tensor.values
              == expected
          )
  
imports: from __future__ import absolute_import
  import numpy
  import tempfile
  import pytest
  import itertools
  from scipy.sparse import coo_matrix
  from sagemaker.amazon.common import RecordDeserializer, write_numpy_to_dense_tensor, read_recordio, RecordSerializer, write_spmatrix_to_sparse_tensor
  from sagemaker.amazon.record_pb2 import Record
label_desc: Use image node_id 1 for calling a global function with example usage: test_serializer() without return types